I'm using the CBL 110mm since first introduction (if I remember well around 2008). The device itself is very well conceived. It's not a simple "grey card", it takes into account reflections and refraction thanks the unique patterns they're using on it's surface. On the back it's a grey card. So it's a must have for any night photographer working in mixed lights conditions, in terms of nature (fluorescent, mixed tungsten etc) and temperature. With a wide angle lens as the DP1M the biggest diameter is the best to use.

No experience with the DPM till now, this is why I was asking how MERRILLs work with custom white balance and, specifically, with the CBL. The Foveon sensors has an incredible amount of detail but somebody (as in the thread you linked) complains about colors reproduction, especially in hard light conditions.

Uwe has ordered the CBL so I trust we'll be able to have his report as soon as he can...